1. Field of the Invention
This invention relates to lightweight continuous guideway structure for monorail trains.
2. The Prior Art
Elevated monorail trains are becoming a popular, efficient and environmentally clean method of mass transportation, and are potentially a significant factor in energy conservation. In general, tracks for monorail trains are assembled from fabricated cast concrete or rolled steel sections of uniform length, weight, and structural strength. Since the track sections are thus designed for maximum stresses along the entire length of each section, considerable excess weight in the track, which must be supported by columns, is a result. This excess weight is not only expensive but complicates transport, erection and support of the track assembly.
Cast concrete tracks are, in addition, expensive to fabricate and difficult to maintain. Generally, center grooves or troughs are cast in the top surface of concrete tracks to provide surfaces along which guide wheels of the monorail train run. These troughs accumulate water, ice, and debris and must periodically be cleaned.
Fabrication of steel track sections also presents certain problems. Due to the high coefficient of thermal expansion in steel, track sections constructed to fit between preplaced support columns often need modification on site to compensate for temperature induced expansion or contraction of the track. Electrical conduit carrying the power to run the trains is often poorly protected or inaccessible for maintenance in steel tracks as well as in concrete tracks.
In view of the foregoing problems, an improved monorail guide structure is needed which is lightweight yet strong enough to support the loads placed upon it by a monorail train. Such a track should be reinforceable on site at points of varying and increasing stress loads. The on site reinforceability should minimize the on site modification problems encountered in steel track fabrication and material consumption should be significantly reduced. A smooth ride should be derived from the surface of the track. Conduits should be protected and easily accessible for maintenance. Such an improved track assembly is disclosed herein.